University of Natural Resources and Life Sciences, Vienna (BOKU) - Research portal
Gewählte Master / Diploma Thesis:
Michael Kronsteiner
(2002):
Chemische und enzymatische Synthese von N-Acetyl-mannosaminuronsäure als Substrat für die Aminotransferase WbpE aus Pseudomonas aeruginosa.
Master / Diploma Thesis,
BOKU-Universität für Bodenkultur.
UB BOKU
obvsg
- Abstract:
- Chemical und enzymatical synthesis of UDP N-Acetylmannosaminuronic acid, as a substrate for the aminotransferase WbpE from Pseudomonas aeruginosa WbpE is the candidate enzyme for the amination of UDP-2-acetamido-2-deoxy-alpha-D-mannopyranosyluronic acid forming UDP-2-acetamido-3-amino-2,3-dideoxy-alpha-D-mannopyranosyluronic acid in the biosynthetic pathway for the O-specific chain of Pseudomonas aeruginosa PAO1 serotype O5 (IATS). The confirmation of the function of WbpE requires the substrate UDP-2-acetamido-2-deoxy-alpha-D-mannopyranosyluronic acid. The nucleotide-activated sugar was chemically synthesized starting from 2-acetamido-2-deoxy-D-mannose. The selective oxidation of UDP-2-acetamido-2-desoxy-alpha-D-mannopyranose was achieved using platinum catalyst and oxygen, whereas TEMPO-oxidation did not yield the desired product. However, this method facilitated the efficient production of 2-acetamido-2-deoxy-alpha-D-mannopyranosyluronic acid phosphate. All products were characterized by physical and spectroscopic methods. As an alternative to the chemical procedure the synthesis of UDP-2-acetamido-2-desoxy-alpha-D-mannopyranosyluronic acid was also carried out enzymatically. For this purpose the enzymes Cap5O and Cap5P from Staphylococcus aureus were applied in a coupled assay together with UDP-2-acetamido-alpha-D-glucopyranose. The identity of the chemically and the enzymatically synthesized products was shown by capillary electrophoresis. However, evidence for the putative function of WbpE could not be supplied.
- Beurteilende(r): Kosma Paul